Lolicon Land

http://www.dlsite.com/maniax/work/=/product_id/RJ223929A man intruded into an academy and took a girl by means of hypnosis.
To save her, her big sister has to play a game offered by the man.
If the big sister wins the game, he will release younger sister. However, a piece of her personality will be taken away and he will rape her every time the big sister loses the game.
Her entire personality will be lost if the big sister fails a number of times…